LIFE CYCLE ANALYSIS
Does driving an electric car help decarbonize the economy?
By Pierre-Olivier Roy
In 2016, CIRAIG embarked on an environmental life cycle assessment that dug into electric vehicles’ inputs, outputs, and environmental impacts—from material extraction to end of life. The aim? Determine whether driving an electric car can help decarbonize an economy.
The answer? It depends. On one level, we confirmed expectations: an electric car is only as green as the power grid used to recharge it—greenhouse gas (GHG) emissions during an electric car’s lifetime are heavily dependent on the country’s electricity-grid mix. A grid with nearly 99 percent renewable energy from hydroelectricity and wind energy, such as the one in Quebec, presented far lower GHG emissions than a grid mix based on fossil fuels (e.g., Germany) or a grid mix which relies more heavily on coal-based electricity (e.g., China).
But here’s the kicker. Even with the cleanest grid mix (Fig. 1), the distance you drive an electric car relative to a conventional vehicle determines whether it is environmentally worthwhile to make the leap to electric. And this is especially true in countries that have a highly carbon-intensive grid mix (Fig. 2).
You would need to drive an electric car more than 50,000 km in Quebec and 150,000 km in Germany to outcompete a conventional car in terms of greenhouse gas emissions
That’s because manufacturing electric cars requires more aluminum (to limit the additional weight of the batteries), more copper (for the electrical system), and more lithium and rare-earth elements than a conventional car. Producing these materials in a worldwide economy emits more greenhouse gases than the production of steel and iron for conventional cars. During its entire life cycle, a 100 percent electric vehicle would emit a similar amount of GHG emissions as a conventional car would at around 50,000 kilometers in Quebec—and at about 150,000 kilometers in Germany. In China, conventional and electric vehicles cannot be differentiated, whatever the distance, indicating that greening the grid mix in certain countries should be a priority prior to switching to electric vehicles.
So what’s the greenest drive to work—especially if it’s relatively close by? With an evolving electric car autonomy (currently at more than 100 kilometers), substituting your conventional car for an electric car and driving it daily for as long as possible (especially with a low-carbon intensive grid mix) seems the way to go. Even better, share your ride and reduce the total number of cars on the road.
The International Reference Centre for the Life Cycle of Products, Processes, and Services (CIRAIG). 2016. Comparison of electric vehicles and conventional vehicles in the Québec context.
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